1. Field of the Invention
The present invention relates to an easy-to-hold hand pump that allows the user to hold the hand pump easily during use.
2. Description of the Related Art
FIG. 12 of the drawings illustrates a conventional hand pump comprising a handle 11xe2x80x2 to which an end of a piston rod 12xe2x80x2 is securely attached. Attached to the other end of the piston rod 12xe2x80x2 is a piston 14xe2x80x2 that is slidably received in a cylinder 13xe2x80x2. A head 15xe2x80x2 is attached to an end of the cylinder 13xe2x80x2 for engaging with a bicycle tire valve or the like and thus inflating the bicycle tire upon reciprocating operation of the handle 11xe2x80x2. It was, however, found that the user""s hand tends to slip from the handle 11xe2x80x2 during operation. FIG. 13 illustrates another conventional hand pump comprising a handle 20xe2x80x2 having two foldable handgrips 23xe2x80x2. A piston rod 21xe2x80x2 is attached to the handle 20xe2x80x2 at an end thereof. A piston 25xe2x80x2 is attached to the other end of the piston rod 21xe2x80x2 and slidably received in a cylinder 24xe2x80x2. A head 26xe2x80x2 is attached to an end of the cylinder 24xe2x80x2 for engaging with a bicycle tire valve or the like. The handgrips 23xe2x80x2 can be pivoted to an operative position indicated by 23xe2x80x3 for inflating the bicycle tire. However, the inflating effect is poor, as the user""s fingers often impinge the other end of the cylinder 24xe2x80x2 during operation. In addition, no means is provided to secure the handgrips 23xe2x80x2 and the cylinder 24xe2x80x2 in place when not in use. FIG. 14 illustrates a further conventional hand pump comprising a handle 50xe2x80x2 to which an end of a cylinder 40xe2x80x2 is pivotally engaged at 60xe2x80x2. A piston rod 34xe2x80x2 includes a first end securely engaged with a head 32xe2x80x2 and a second end with a piston 36xe2x80x2 that is slidably received in the cylinder 40xe2x80x2. The handle 50xe2x80x2 is made of a plastic material and thus tends to disengage from the cylinder 40xe2x80x2 when the plastic material fatigues.
It is an object of the present invention to provide an easy-to-hold hand pump that allows the user to hold the hand pump easily during use.
In accordance with a first aspect of the invention, a hand pump comprises:
a head including a valve-engaging portion for engaging with a valve of an article to be inflated;
a cylinder including a first end connected to the head and a second end;
a piston rod including a first end and a second end, a piston being securely mounted to the first end of the piston rod for reciprocation in the cylinder, the second end of the piston rod extending beyond the second end of the cylinder;
a first handle attached to the second end of the piston rod; and
a second handle attached to the head.
In accordance with a second aspect of the invention, a hand pump comprises:
a head including a valve-engaging portion for engaging with a valve of an article to be inflated;
a cylinder including a first end connected to the head and a second end;
a piston rod including a first end and a second end, a piston being securely mounted to the first end of the piston rod for reciprocation in the cylinder, the second end of the piston rod extending beyond the second end of the cylinder; and
a handle comprising an engaging portion securely connected to the second end of the piston rod, the handle further comprising a grip portion extending from the engaging portion and being at an angle with the engaging portion, the engaging portion of the handle comprising a fingerrest extending downward from a lower side thereof.
In accordance with a third aspect of the invention, a hand pump comprises:
a head including a valve-engaging portion for engaging with a valve of an article to be inflated;
an outer cylinder including a first end connected to the head and a second end;
an inner cylinder including a first end and a second end, a first piston being securely mounted to the first end of the inner cylinder for reciprocation in the outer cylinder;
a piston rod including a first end and a second end, a second piston being securely mounted to the first end of the piston rod for reciprocation in the inner cylinder, the second end of the piston rod extending beyond the second end of the inner cylinder; and
a handle comprising an engaging portion securely connected to the second end of the piston rod, the handle further comprising a grip portion extending from the engaging portion and being at an angle with the engaging portion, the engaging portion of the handle comprising a fingerrest extending downward from a lower side thereof.
The second handle is pivotally mounted to the head. In an embodiment of the invention, the head includes two spaced lugs having aligned pivot holes. A pin extends through the pivot holes of the lugs and an end of the second handle. One of the lugs comprises two positioning holes that correspond to an inoperative position of the second handle and an operative position of the second handle, respectively. The end of the second handle comprises a protrusion releasably engaged in one of the positioning holes.
A securing means is provided for securing the engaging portion of the handle to the second end of the outer cylinder when not in use. The securing means comprises a button pivotally mounted to the engaging portion of the handle and including an engaging member. The second end of the outer cylinder is enclosed by an engaging tube through which the piston rod extends. The engaging tube includes a positioning slot in an outer periphery thereof. The engaging member is releasably engaged in the positioning slot of the engaging tube. The engaging member of the button includes a first positioning groove and a second positioning groove that correspond to an engaging position in which the engaging member is engaged in the positioning slot of the engaging tube and a non-engaging position in which the engaging member is disengaged from the positioning slot of the engaging tube. The engaging portion of the handle comprises a protrusion that is releasably engaged in one of the first positioning groove and the second positioning groove.